Effects of dorsal and ventral visual pathway lesions on visual vigilance
Spatial attention depends on a network of structures along the occipito- parietal pathways. This study examined anatomical substrates of visual vigilance in 19 patients with MR/CT verified occipital-temporal pathway lesions (11-L hemisphere, 8-R hemisphere) and 17 occipito-parietal pathway lesions (8-L hemisphere, 9-R hemisphere). We also tested 145 neurologically normal controls. Subjects completed the Starry Night task. Each trial required immediate response to the appearance or disappearance, at unpredictable locations and intervals, of a single element in a multi-element random dot display. We eliminated trials presented in the regions of visual field loss to avoid confounding vigilance impairments with sensory deficits, and adjusted vigilance scores for age, visual acuity and contrast sensitivity. Results showed that the dorsal and ventral pathway lesion groups each scored worse than the non-lesion subjects on all vigilance measures (all ps < .008). Within these groups, right hemisphere cases showed worse vigilance scores than left hemisphere cases (all ps < .04). Unilateral lesions in visual association cortex impaired vigilance scores in both hemifields. However, visual vigilance deficits did not differ significantly between the dorsal and ventral pathway lesion groups, suggesting that dorsal and ventral visual association cortices, particularly in the right hemisphere, are important for maintaining visual vigilance, compatible with the reported advantages of the right hemisphere in visual spatial processing. Unilateral lesions produce bilateral deficits (Rizzo & Robin, 1996). Surprisingly, there was no evidence to support an advantage of the dorsal over ventral visual association cortices for maintaining visual vigilance.
Journal of Vision
Philippi, Carissa; Sparks, JonDavid; Marron, Maureen; and Rizzo, Matthew, "Effects of dorsal and ventral visual pathway lesions on visual vigilance" (2010). Psychology Faculty Works. 80.